Fix python signature?

Author: m-kuhn

python/core/auto_generated/qgsvectorlayer.sip.in

@@ -2354,7 +2354,7 @@ Is emitted, when editing on this layer has started
 Is emitted, when edited changes successfully have been written to the data provider
 %End
 
-    void canCommitChanges( bool &canCommit );
+    void canCommitChanges( bool *canCommit );
 %Docstring
 Emitted when a layer wants to commit changes to the data provider.
 Can be used to prevent the layer from being saved by setting ``canCommit`` to false.

src/core/qgsvectorlayer.cpp

@@ -2926,7 +2926,7 @@ bool QgsVectorLayer::commitChanges()
 
   bool canCommit = true;
 
-  emit canCommitChanges( canCommit );
+  emit canCommitChanges( &canCommit );
 
   if ( !canCommit )
     return false;

src/core/qgsvectorlayer.h

@@ -2122,7 +2122,7 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer, public QgsExpressionConte
      *
      * \since QGIS 3.4
      */
-    void canCommitChanges( bool &canCommit );
+    void canCommitChanges( bool *canCommit );
 
     //! Is emitted, before changes are committed to the data provider
     void beforeCommitChanges();